This invention relates to a improved pressure gauge and more particularly to a pressure gauge adaptable to simultaneously indicate multi-linear scale readings of tire pressure.
In the known pressure gauge there exists an inherent problem in that it can only be used to indicate one linear scale of tire pressure, such as LBS/in2, KPA, BAR or Kg/cm2, at a time.
The above-mentioned limitation presents another problem with regard to the production of the pressure gauge. Since only one linear scale readings is provided, the gauge must be produced a multiple number of times to satisfy the different measurement standards of the country for which it is being manufactured. As a result, optimum conditions for cost efficient mass production of the pressure gauge can not be achieved.
The conventional pressure gauge as shown in FIGS. 1 and 2 includes a tubular member with a hollow interior and a first and a second end. The pressure gauge also includes a tire valve engaging head attached to the first end of the tubular member and a compression spring having a first and a second end. The compression spring is located within the tubular member. Also provided on the pressure gauge are a piston movably at the first end of the compression spring, a graduated bar means movably within the compression spring, and a cover means with an opening frictionally engaging the graduated bar means and fitting into the second end of the tubular member.